g_mirror.c revision 163836
1/*-
2 * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/mirror/g_mirror.c 163836 2006-10-31 21:23:51Z pjd $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/mutex.h>
37#include <sys/bio.h>
38#include <sys/sysctl.h>
39#include <sys/malloc.h>
40#include <sys/eventhandler.h>
41#include <vm/uma.h>
42#include <geom/geom.h>
43#include <sys/proc.h>
44#include <sys/kthread.h>
45#include <sys/sched.h>
46#include <geom/mirror/g_mirror.h>
47
48
49static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
50
51SYSCTL_DECL(_kern_geom);
52SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0, "GEOM_MIRROR stuff");
53u_int g_mirror_debug = 0;
54TUNABLE_INT("kern.geom.mirror.debug", &g_mirror_debug);
55SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RW, &g_mirror_debug, 0,
56    "Debug level");
57static u_int g_mirror_timeout = 4;
58TUNABLE_INT("kern.geom.mirror.timeout", &g_mirror_timeout);
59SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RW, &g_mirror_timeout,
60    0, "Time to wait on all mirror components");
61static u_int g_mirror_idletime = 5;
62TUNABLE_INT("kern.geom.mirror.idletime", &g_mirror_idletime);
63SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RW,
64    &g_mirror_idletime, 0, "Mark components as clean when idling");
65static u_int g_mirror_disconnect_on_failure = 1;
66TUNABLE_INT("kern.geom.mirror.disconnect_on_failure",
67    &g_mirror_disconnect_on_failure);
68SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RW,
69    &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
70static u_int g_mirror_syncreqs = 2;
71TUNABLE_INT("kern.geom.mirror.sync_requests", &g_mirror_syncreqs);
72SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
73    &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
74
75#define	MSLEEP(ident, mtx, priority, wmesg, timeout)	do {		\
76	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));	\
77	msleep((ident), (mtx), (priority), (wmesg), (timeout));		\
78	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));	\
79} while (0)
80
81static eventhandler_tag g_mirror_pre_sync = NULL;
82
83static int g_mirror_destroy_geom(struct gctl_req *req, struct g_class *mp,
84    struct g_geom *gp);
85static g_taste_t g_mirror_taste;
86static void g_mirror_init(struct g_class *mp);
87static void g_mirror_fini(struct g_class *mp);
88
89struct g_class g_mirror_class = {
90	.name = G_MIRROR_CLASS_NAME,
91	.version = G_VERSION,
92	.ctlreq = g_mirror_config,
93	.taste = g_mirror_taste,
94	.destroy_geom = g_mirror_destroy_geom,
95	.init = g_mirror_init,
96	.fini = g_mirror_fini
97};
98
99
100static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
101static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
102static void g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force);
103static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
104    struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
105static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
106static void g_mirror_register_request(struct bio *bp);
107static void g_mirror_sync_release(struct g_mirror_softc *sc);
108
109
110static const char *
111g_mirror_disk_state2str(int state)
112{
113
114	switch (state) {
115	case G_MIRROR_DISK_STATE_NONE:
116		return ("NONE");
117	case G_MIRROR_DISK_STATE_NEW:
118		return ("NEW");
119	case G_MIRROR_DISK_STATE_ACTIVE:
120		return ("ACTIVE");
121	case G_MIRROR_DISK_STATE_STALE:
122		return ("STALE");
123	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
124		return ("SYNCHRONIZING");
125	case G_MIRROR_DISK_STATE_DISCONNECTED:
126		return ("DISCONNECTED");
127	case G_MIRROR_DISK_STATE_DESTROY:
128		return ("DESTROY");
129	default:
130		return ("INVALID");
131	}
132}
133
134static const char *
135g_mirror_device_state2str(int state)
136{
137
138	switch (state) {
139	case G_MIRROR_DEVICE_STATE_STARTING:
140		return ("STARTING");
141	case G_MIRROR_DEVICE_STATE_RUNNING:
142		return ("RUNNING");
143	default:
144		return ("INVALID");
145	}
146}
147
148static const char *
149g_mirror_get_diskname(struct g_mirror_disk *disk)
150{
151
152	if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
153		return ("[unknown]");
154	return (disk->d_name);
155}
156
157/*
158 * --- Events handling functions ---
159 * Events in geom_mirror are used to maintain disks and device status
160 * from one thread to simplify locking.
161 */
162static void
163g_mirror_event_free(struct g_mirror_event *ep)
164{
165
166	free(ep, M_MIRROR);
167}
168
169int
170g_mirror_event_send(void *arg, int state, int flags)
171{
172	struct g_mirror_softc *sc;
173	struct g_mirror_disk *disk;
174	struct g_mirror_event *ep;
175	int error;
176
177	ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
178	G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
179	if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
180		disk = NULL;
181		sc = arg;
182	} else {
183		disk = arg;
184		sc = disk->d_softc;
185	}
186	ep->e_disk = disk;
187	ep->e_state = state;
188	ep->e_flags = flags;
189	ep->e_error = 0;
190	mtx_lock(&sc->sc_events_mtx);
191	TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
192	mtx_unlock(&sc->sc_events_mtx);
193	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
194	mtx_lock(&sc->sc_queue_mtx);
195	wakeup(sc);
196	mtx_unlock(&sc->sc_queue_mtx);
197	if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
198		return (0);
199	sx_assert(&sc->sc_lock, SX_XLOCKED);
200	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
201	sx_xunlock(&sc->sc_lock);
202	while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
203		mtx_lock(&sc->sc_events_mtx);
204		MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
205		    hz * 5);
206	}
207	error = ep->e_error;
208	g_mirror_event_free(ep);
209	sx_xlock(&sc->sc_lock);
210	return (error);
211}
212
213static struct g_mirror_event *
214g_mirror_event_get(struct g_mirror_softc *sc)
215{
216	struct g_mirror_event *ep;
217
218	mtx_lock(&sc->sc_events_mtx);
219	ep = TAILQ_FIRST(&sc->sc_events);
220	mtx_unlock(&sc->sc_events_mtx);
221	return (ep);
222}
223
224static void
225g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
226{
227
228	mtx_lock(&sc->sc_events_mtx);
229	TAILQ_REMOVE(&sc->sc_events, ep, e_next);
230	mtx_unlock(&sc->sc_events_mtx);
231}
232
233static void
234g_mirror_event_cancel(struct g_mirror_disk *disk)
235{
236	struct g_mirror_softc *sc;
237	struct g_mirror_event *ep, *tmpep;
238
239	sc = disk->d_softc;
240	sx_assert(&sc->sc_lock, SX_XLOCKED);
241
242	mtx_lock(&sc->sc_events_mtx);
243	TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
244		if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
245			continue;
246		if (ep->e_disk != disk)
247			continue;
248		TAILQ_REMOVE(&sc->sc_events, ep, e_next);
249		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
250			g_mirror_event_free(ep);
251		else {
252			ep->e_error = ECANCELED;
253			wakeup(ep);
254		}
255	}
256	mtx_unlock(&sc->sc_events_mtx);
257}
258
259/*
260 * Return the number of disks in given state.
261 * If state is equal to -1, count all connected disks.
262 */
263u_int
264g_mirror_ndisks(struct g_mirror_softc *sc, int state)
265{
266	struct g_mirror_disk *disk;
267	u_int n = 0;
268
269	sx_assert(&sc->sc_lock, SX_LOCKED);
270
271	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
272		if (state == -1 || disk->d_state == state)
273			n++;
274	}
275	return (n);
276}
277
278/*
279 * Find a disk in mirror by its disk ID.
280 */
281static struct g_mirror_disk *
282g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
283{
284	struct g_mirror_disk *disk;
285
286	sx_assert(&sc->sc_lock, SX_XLOCKED);
287
288	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
289		if (disk->d_id == id)
290			return (disk);
291	}
292	return (NULL);
293}
294
295static u_int
296g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
297{
298	struct bio *bp;
299	u_int nreqs = 0;
300
301	mtx_lock(&sc->sc_queue_mtx);
302	TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
303		if (bp->bio_from == cp)
304			nreqs++;
305	}
306	mtx_unlock(&sc->sc_queue_mtx);
307	return (nreqs);
308}
309
310static int
311g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
312{
313
314	if (cp->index > 0) {
315		G_MIRROR_DEBUG(2,
316		    "I/O requests for %s exist, can't destroy it now.",
317		    cp->provider->name);
318		return (1);
319	}
320	if (g_mirror_nrequests(sc, cp) > 0) {
321		G_MIRROR_DEBUG(2,
322		    "I/O requests for %s in queue, can't destroy it now.",
323		    cp->provider->name);
324		return (1);
325	}
326	return (0);
327}
328
329static void
330g_mirror_destroy_consumer(void *arg, int flags __unused)
331{
332	struct g_consumer *cp;
333
334	g_topology_assert();
335
336	cp = arg;
337	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
338	g_detach(cp);
339	g_destroy_consumer(cp);
340}
341
342static void
343g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
344{
345	struct g_provider *pp;
346	int retaste_wait;
347
348	g_topology_assert();
349
350	cp->private = NULL;
351	if (g_mirror_is_busy(sc, cp))
352		return;
353	pp = cp->provider;
354	retaste_wait = 0;
355	if (cp->acw == 1) {
356		if ((pp->geom->flags & G_GEOM_WITHER) == 0)
357			retaste_wait = 1;
358	}
359	G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
360	    -cp->acw, -cp->ace, 0);
361	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
362		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
363	if (retaste_wait) {
364		/*
365		 * After retaste event was send (inside g_access()), we can send
366		 * event to detach and destroy consumer.
367		 * A class, which has consumer to the given provider connected
368		 * will not receive retaste event for the provider.
369		 * This is the way how I ignore retaste events when I close
370		 * consumers opened for write: I detach and destroy consumer
371		 * after retaste event is sent.
372		 */
373		g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
374		return;
375	}
376	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
377	g_detach(cp);
378	g_destroy_consumer(cp);
379}
380
381static int
382g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
383{
384	struct g_consumer *cp;
385	int error;
386
387	g_topology_assert_not();
388	KASSERT(disk->d_consumer == NULL,
389	    ("Disk already connected (device %s).", disk->d_softc->sc_name));
390
391	g_topology_lock();
392	cp = g_new_consumer(disk->d_softc->sc_geom);
393	error = g_attach(cp, pp);
394	if (error != 0) {
395		g_destroy_consumer(cp);
396		g_topology_unlock();
397		return (error);
398	}
399	error = g_access(cp, 1, 1, 1);
400	if (error != 0) {
401		g_detach(cp);
402		g_destroy_consumer(cp);
403		g_topology_unlock();
404		G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
405		    pp->name, error);
406		return (error);
407	}
408	g_topology_unlock();
409	disk->d_consumer = cp;
410	disk->d_consumer->private = disk;
411	disk->d_consumer->index = 0;
412
413	G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
414	return (0);
415}
416
417static void
418g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
419{
420
421	g_topology_assert();
422
423	if (cp == NULL)
424		return;
425	if (cp->provider != NULL)
426		g_mirror_kill_consumer(sc, cp);
427	else
428		g_destroy_consumer(cp);
429}
430
431/*
432 * Initialize disk. This means allocate memory, create consumer, attach it
433 * to the provider and open access (r1w1e1) to it.
434 */
435static struct g_mirror_disk *
436g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
437    struct g_mirror_metadata *md, int *errorp)
438{
439	struct g_mirror_disk *disk;
440	int error;
441
442	disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
443	if (disk == NULL) {
444		error = ENOMEM;
445		goto fail;
446	}
447	disk->d_softc = sc;
448	error = g_mirror_connect_disk(disk, pp);
449	if (error != 0)
450		goto fail;
451	disk->d_id = md->md_did;
452	disk->d_state = G_MIRROR_DISK_STATE_NONE;
453	disk->d_priority = md->md_priority;
454	disk->d_delay.sec = 0;
455	disk->d_delay.frac = 0;
456	binuptime(&disk->d_last_used);
457	disk->d_flags = md->md_dflags;
458	if (md->md_provider[0] != '\0')
459		disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
460	disk->d_sync.ds_consumer = NULL;
461	disk->d_sync.ds_offset = md->md_sync_offset;
462	disk->d_sync.ds_offset_done = md->md_sync_offset;
463	disk->d_genid = md->md_genid;
464	disk->d_sync.ds_syncid = md->md_syncid;
465	if (errorp != NULL)
466		*errorp = 0;
467	return (disk);
468fail:
469	if (errorp != NULL)
470		*errorp = error;
471	if (disk != NULL)
472		free(disk, M_MIRROR);
473	return (NULL);
474}
475
476static void
477g_mirror_destroy_disk(struct g_mirror_disk *disk)
478{
479	struct g_mirror_softc *sc;
480
481	g_topology_assert_not();
482	sc = disk->d_softc;
483	sx_assert(&sc->sc_lock, SX_XLOCKED);
484
485	LIST_REMOVE(disk, d_next);
486	g_mirror_event_cancel(disk);
487	if (sc->sc_hint == disk)
488		sc->sc_hint = NULL;
489	switch (disk->d_state) {
490	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
491		g_mirror_sync_stop(disk, 1);
492		/* FALLTHROUGH */
493	case G_MIRROR_DISK_STATE_NEW:
494	case G_MIRROR_DISK_STATE_STALE:
495	case G_MIRROR_DISK_STATE_ACTIVE:
496		g_topology_lock();
497		g_mirror_disconnect_consumer(sc, disk->d_consumer);
498		g_topology_unlock();
499		free(disk, M_MIRROR);
500		break;
501	default:
502		KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
503		    g_mirror_get_diskname(disk),
504		    g_mirror_disk_state2str(disk->d_state)));
505	}
506}
507
508static void
509g_mirror_destroy_device(struct g_mirror_softc *sc)
510{
511	struct g_mirror_disk *disk;
512	struct g_mirror_event *ep;
513	struct g_geom *gp;
514	struct g_consumer *cp, *tmpcp;
515
516	g_topology_assert_not();
517	sx_assert(&sc->sc_lock, SX_XLOCKED);
518
519	gp = sc->sc_geom;
520	if (sc->sc_provider != NULL)
521		g_mirror_destroy_provider(sc);
522	for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
523	    disk = LIST_FIRST(&sc->sc_disks)) {
524		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
525		g_mirror_update_metadata(disk);
526		g_mirror_destroy_disk(disk);
527	}
528	while ((ep = g_mirror_event_get(sc)) != NULL) {
529		g_mirror_event_remove(sc, ep);
530		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
531			g_mirror_event_free(ep);
532		else {
533			ep->e_error = ECANCELED;
534			ep->e_flags |= G_MIRROR_EVENT_DONE;
535			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
536			mtx_lock(&sc->sc_events_mtx);
537			wakeup(ep);
538			mtx_unlock(&sc->sc_events_mtx);
539		}
540	}
541	callout_drain(&sc->sc_callout);
542
543	g_topology_lock();
544	LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
545		g_mirror_disconnect_consumer(sc, cp);
546	}
547	g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
548	G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
549	g_wither_geom(gp, ENXIO);
550	g_topology_unlock();
551	mtx_destroy(&sc->sc_queue_mtx);
552	mtx_destroy(&sc->sc_events_mtx);
553	sx_xunlock(&sc->sc_lock);
554	sx_destroy(&sc->sc_lock);
555}
556
557static void
558g_mirror_orphan(struct g_consumer *cp)
559{
560	struct g_mirror_disk *disk;
561
562	g_topology_assert();
563
564	disk = cp->private;
565	if (disk == NULL)
566		return;
567	disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
568	g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
569	    G_MIRROR_EVENT_DONTWAIT);
570}
571
572/*
573 * Function should return the next active disk on the list.
574 * It is possible that it will be the same disk as given.
575 * If there are no active disks on list, NULL is returned.
576 */
577static __inline struct g_mirror_disk *
578g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
579{
580	struct g_mirror_disk *dp;
581
582	for (dp = LIST_NEXT(disk, d_next); dp != disk;
583	    dp = LIST_NEXT(dp, d_next)) {
584		if (dp == NULL)
585			dp = LIST_FIRST(&sc->sc_disks);
586		if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
587			break;
588	}
589	if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
590		return (NULL);
591	return (dp);
592}
593
594static struct g_mirror_disk *
595g_mirror_get_disk(struct g_mirror_softc *sc)
596{
597	struct g_mirror_disk *disk;
598
599	if (sc->sc_hint == NULL) {
600		sc->sc_hint = LIST_FIRST(&sc->sc_disks);
601		if (sc->sc_hint == NULL)
602			return (NULL);
603	}
604	disk = sc->sc_hint;
605	if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
606		disk = g_mirror_find_next(sc, disk);
607		if (disk == NULL)
608			return (NULL);
609	}
610	sc->sc_hint = g_mirror_find_next(sc, disk);
611	return (disk);
612}
613
614static int
615g_mirror_write_metadata(struct g_mirror_disk *disk,
616    struct g_mirror_metadata *md)
617{
618	struct g_mirror_softc *sc;
619	struct g_consumer *cp;
620	off_t offset, length;
621	u_char *sector;
622	int error = 0;
623
624	g_topology_assert_not();
625	sc = disk->d_softc;
626	sx_assert(&sc->sc_lock, SX_LOCKED);
627
628	cp = disk->d_consumer;
629	KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
630	KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
631	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
632	    ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
633	    cp->acw, cp->ace));
634	length = cp->provider->sectorsize;
635	offset = cp->provider->mediasize - length;
636	sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
637	if (md != NULL)
638		mirror_metadata_encode(md, sector);
639	error = g_write_data(cp, offset, sector, length);
640	free(sector, M_MIRROR);
641	if (error != 0) {
642		if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
643			disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
644			G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
645			    "(device=%s, error=%d).",
646			    g_mirror_get_diskname(disk), sc->sc_name, error);
647		} else {
648			G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
649			    "(device=%s, error=%d).",
650			    g_mirror_get_diskname(disk), sc->sc_name, error);
651		}
652		if (g_mirror_disconnect_on_failure &&
653		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
654			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
655			g_mirror_event_send(disk,
656			    G_MIRROR_DISK_STATE_DISCONNECTED,
657			    G_MIRROR_EVENT_DONTWAIT);
658		}
659	}
660	return (error);
661}
662
663static int
664g_mirror_clear_metadata(struct g_mirror_disk *disk)
665{
666	int error;
667
668	g_topology_assert_not();
669	sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
670
671	error = g_mirror_write_metadata(disk, NULL);
672	if (error == 0) {
673		G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
674		    g_mirror_get_diskname(disk));
675	} else {
676		G_MIRROR_DEBUG(0,
677		    "Cannot clear metadata on disk %s (error=%d).",
678		    g_mirror_get_diskname(disk), error);
679	}
680	return (error);
681}
682
683void
684g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
685    struct g_mirror_metadata *md)
686{
687
688	strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
689	md->md_version = G_MIRROR_VERSION;
690	strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
691	md->md_mid = sc->sc_id;
692	md->md_all = sc->sc_ndisks;
693	md->md_slice = sc->sc_slice;
694	md->md_balance = sc->sc_balance;
695	md->md_genid = sc->sc_genid;
696	md->md_mediasize = sc->sc_mediasize;
697	md->md_sectorsize = sc->sc_sectorsize;
698	md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
699	bzero(md->md_provider, sizeof(md->md_provider));
700	if (disk == NULL) {
701		md->md_did = arc4random();
702		md->md_priority = 0;
703		md->md_syncid = 0;
704		md->md_dflags = 0;
705		md->md_sync_offset = 0;
706		md->md_provsize = 0;
707	} else {
708		md->md_did = disk->d_id;
709		md->md_priority = disk->d_priority;
710		md->md_syncid = disk->d_sync.ds_syncid;
711		md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
712		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
713			md->md_sync_offset = disk->d_sync.ds_offset_done;
714		else
715			md->md_sync_offset = 0;
716		if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
717			strlcpy(md->md_provider,
718			    disk->d_consumer->provider->name,
719			    sizeof(md->md_provider));
720		}
721		md->md_provsize = disk->d_consumer->provider->mediasize;
722	}
723}
724
725void
726g_mirror_update_metadata(struct g_mirror_disk *disk)
727{
728	struct g_mirror_softc *sc;
729	struct g_mirror_metadata md;
730	int error;
731
732	g_topology_assert_not();
733	sc = disk->d_softc;
734	sx_assert(&sc->sc_lock, SX_LOCKED);
735
736	g_mirror_fill_metadata(sc, disk, &md);
737	error = g_mirror_write_metadata(disk, &md);
738	if (error == 0) {
739		G_MIRROR_DEBUG(2, "Metadata on %s updated.",
740		    g_mirror_get_diskname(disk));
741	} else {
742		G_MIRROR_DEBUG(0,
743		    "Cannot update metadata on disk %s (error=%d).",
744		    g_mirror_get_diskname(disk), error);
745	}
746}
747
748static void
749g_mirror_bump_syncid(struct g_mirror_softc *sc)
750{
751	struct g_mirror_disk *disk;
752
753	g_topology_assert_not();
754	sx_assert(&sc->sc_lock, SX_XLOCKED);
755	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
756	    ("%s called with no active disks (device=%s).", __func__,
757	    sc->sc_name));
758
759	sc->sc_syncid++;
760	G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
761	    sc->sc_syncid);
762	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
763		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
764		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
765			disk->d_sync.ds_syncid = sc->sc_syncid;
766			g_mirror_update_metadata(disk);
767		}
768	}
769}
770
771static void
772g_mirror_bump_genid(struct g_mirror_softc *sc)
773{
774	struct g_mirror_disk *disk;
775
776	g_topology_assert_not();
777	sx_assert(&sc->sc_lock, SX_XLOCKED);
778	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
779	    ("%s called with no active disks (device=%s).", __func__,
780	    sc->sc_name));
781
782	sc->sc_genid++;
783	G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
784	    sc->sc_genid);
785	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
786		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
787		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
788			disk->d_genid = sc->sc_genid;
789			g_mirror_update_metadata(disk);
790		}
791	}
792}
793
794static int
795g_mirror_idle(struct g_mirror_softc *sc, int acw)
796{
797	struct g_mirror_disk *disk;
798	int timeout;
799
800	g_topology_assert_not();
801	sx_assert(&sc->sc_lock, SX_XLOCKED);
802
803	if (sc->sc_provider == NULL)
804		return (0);
805	if (sc->sc_idle)
806		return (0);
807	if (sc->sc_writes > 0)
808		return (0);
809	if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
810		timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
811		if (timeout > 0)
812			return (timeout);
813	}
814	sc->sc_idle = 1;
815	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
816		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
817			continue;
818		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
819		    g_mirror_get_diskname(disk), sc->sc_name);
820		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
821		g_mirror_update_metadata(disk);
822	}
823	return (0);
824}
825
826static void
827g_mirror_unidle(struct g_mirror_softc *sc)
828{
829	struct g_mirror_disk *disk;
830
831	g_topology_assert_not();
832	sx_assert(&sc->sc_lock, SX_XLOCKED);
833
834	sc->sc_idle = 0;
835	sc->sc_last_write = time_uptime;
836	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
837		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
838			continue;
839		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
840		    g_mirror_get_diskname(disk), sc->sc_name);
841		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
842		g_mirror_update_metadata(disk);
843	}
844}
845
846static __inline int
847bintime_cmp(struct bintime *bt1, struct bintime *bt2)
848{
849
850	if (bt1->sec < bt2->sec)
851		return (-1);
852	else if (bt1->sec > bt2->sec)
853		return (1);
854	if (bt1->frac < bt2->frac)
855		return (-1);
856	else if (bt1->frac > bt2->frac)
857		return (1);
858	return (0);
859}
860
861static void
862g_mirror_update_delay(struct g_mirror_disk *disk, struct bio *bp)
863{
864
865	if (disk->d_softc->sc_balance != G_MIRROR_BALANCE_LOAD)
866		return;
867	binuptime(&disk->d_delay);
868	bintime_sub(&disk->d_delay, &bp->bio_t0);
869}
870
871static void
872g_mirror_done(struct bio *bp)
873{
874	struct g_mirror_softc *sc;
875
876	sc = bp->bio_from->geom->softc;
877	bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
878	mtx_lock(&sc->sc_queue_mtx);
879	bioq_disksort(&sc->sc_queue, bp);
880	wakeup(sc);
881	mtx_unlock(&sc->sc_queue_mtx);
882}
883
884static void
885g_mirror_regular_request(struct bio *bp)
886{
887	struct g_mirror_softc *sc;
888	struct g_mirror_disk *disk;
889	struct bio *pbp;
890
891	g_topology_assert_not();
892
893	pbp = bp->bio_parent;
894	sc = pbp->bio_to->geom->softc;
895	bp->bio_from->index--;
896	if (bp->bio_cmd == BIO_WRITE)
897		sc->sc_writes--;
898	disk = bp->bio_from->private;
899	if (disk == NULL) {
900		g_topology_lock();
901		g_mirror_kill_consumer(sc, bp->bio_from);
902		g_topology_unlock();
903	} else {
904		g_mirror_update_delay(disk, bp);
905	}
906
907	pbp->bio_inbed++;
908	KASSERT(pbp->bio_inbed <= pbp->bio_children,
909	    ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
910	    pbp->bio_children));
911	if (bp->bio_error == 0 && pbp->bio_error == 0) {
912		G_MIRROR_LOGREQ(3, bp, "Request delivered.");
913		g_destroy_bio(bp);
914		if (pbp->bio_children == pbp->bio_inbed) {
915			G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
916			pbp->bio_completed = pbp->bio_length;
917			if (pbp->bio_cmd == BIO_WRITE) {
918				bioq_remove(&sc->sc_inflight, pbp);
919				/* Release delayed sync requests if possible. */
920				g_mirror_sync_release(sc);
921			}
922			g_io_deliver(pbp, pbp->bio_error);
923		}
924		return;
925	} else if (bp->bio_error != 0) {
926		if (pbp->bio_error == 0)
927			pbp->bio_error = bp->bio_error;
928		if (disk != NULL) {
929			if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
930				disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
931				G_MIRROR_LOGREQ(0, bp,
932				    "Request failed (error=%d).",
933				    bp->bio_error);
934			} else {
935				G_MIRROR_LOGREQ(1, bp,
936				    "Request failed (error=%d).",
937				    bp->bio_error);
938			}
939			if (g_mirror_disconnect_on_failure &&
940			    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
941			{
942				sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
943				g_mirror_event_send(disk,
944				    G_MIRROR_DISK_STATE_DISCONNECTED,
945				    G_MIRROR_EVENT_DONTWAIT);
946			}
947		}
948		switch (pbp->bio_cmd) {
949		case BIO_DELETE:
950		case BIO_WRITE:
951			pbp->bio_inbed--;
952			pbp->bio_children--;
953			break;
954		}
955	}
956	g_destroy_bio(bp);
957
958	switch (pbp->bio_cmd) {
959	case BIO_READ:
960		if (pbp->bio_inbed < pbp->bio_children)
961			break;
962		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
963			g_io_deliver(pbp, pbp->bio_error);
964		else {
965			pbp->bio_error = 0;
966			mtx_lock(&sc->sc_queue_mtx);
967			bioq_disksort(&sc->sc_queue, pbp);
968			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
969			wakeup(sc);
970			mtx_unlock(&sc->sc_queue_mtx);
971		}
972		break;
973	case BIO_DELETE:
974	case BIO_WRITE:
975		if (pbp->bio_children == 0) {
976			/*
977			 * All requests failed.
978			 */
979		} else if (pbp->bio_inbed < pbp->bio_children) {
980			/* Do nothing. */
981			break;
982		} else if (pbp->bio_children == pbp->bio_inbed) {
983			/* Some requests succeeded. */
984			pbp->bio_error = 0;
985			pbp->bio_completed = pbp->bio_length;
986		}
987		bioq_remove(&sc->sc_inflight, pbp);
988		/* Release delayed sync requests if possible. */
989		g_mirror_sync_release(sc);
990		g_io_deliver(pbp, pbp->bio_error);
991		break;
992	default:
993		KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
994		break;
995	}
996}
997
998static void
999g_mirror_sync_done(struct bio *bp)
1000{
1001	struct g_mirror_softc *sc;
1002
1003	G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
1004	sc = bp->bio_from->geom->softc;
1005	bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
1006	mtx_lock(&sc->sc_queue_mtx);
1007	bioq_disksort(&sc->sc_queue, bp);
1008	wakeup(sc);
1009	mtx_unlock(&sc->sc_queue_mtx);
1010}
1011
1012static void
1013g_mirror_kernel_dump(struct bio *bp)
1014{
1015	struct g_mirror_softc *sc;
1016	struct g_mirror_disk *disk;
1017	struct bio *cbp;
1018	struct g_kerneldump *gkd;
1019
1020	/*
1021	 * We configure dumping to the first component, because this component
1022	 * will be used for reading with 'prefer' balance algorithm.
1023	 * If the component with the higest priority is currently disconnected
1024	 * we will not be able to read the dump after the reboot if it will be
1025	 * connected and synchronized later. Can we do something better?
1026	 */
1027	sc = bp->bio_to->geom->softc;
1028	disk = LIST_FIRST(&sc->sc_disks);
1029
1030	gkd = (struct g_kerneldump *)bp->bio_data;
1031	if (gkd->length > bp->bio_to->mediasize)
1032		gkd->length = bp->bio_to->mediasize;
1033	cbp = g_clone_bio(bp);
1034	if (cbp == NULL) {
1035		g_io_deliver(bp, ENOMEM);
1036		return;
1037	}
1038	cbp->bio_done = g_std_done;
1039	g_io_request(cbp, disk->d_consumer);
1040	G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1041	    g_mirror_get_diskname(disk));
1042}
1043
1044static void
1045g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1046{
1047	struct bio_queue_head queue;
1048	struct g_mirror_disk *disk;
1049	struct g_consumer *cp;
1050	struct bio *cbp;
1051
1052	bioq_init(&queue);
1053	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1054		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1055			continue;
1056		cbp = g_clone_bio(bp);
1057		if (cbp == NULL) {
1058			for (cbp = bioq_first(&queue); cbp != NULL;
1059			    cbp = bioq_first(&queue)) {
1060				bioq_remove(&queue, cbp);
1061				g_destroy_bio(cbp);
1062			}
1063			if (bp->bio_error == 0)
1064				bp->bio_error = ENOMEM;
1065			g_io_deliver(bp, bp->bio_error);
1066			return;
1067		}
1068		bioq_insert_tail(&queue, cbp);
1069		cbp->bio_done = g_std_done;
1070		cbp->bio_caller1 = disk;
1071		cbp->bio_to = disk->d_consumer->provider;
1072	}
1073	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1074		bioq_remove(&queue, cbp);
1075		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1076		disk = cbp->bio_caller1;
1077		cbp->bio_caller1 = NULL;
1078		cp = disk->d_consumer;
1079		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1080		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1081		    cp->acr, cp->acw, cp->ace));
1082		g_io_request(cbp, disk->d_consumer);
1083	}
1084}
1085
1086static void
1087g_mirror_start(struct bio *bp)
1088{
1089	struct g_mirror_softc *sc;
1090
1091	sc = bp->bio_to->geom->softc;
1092	/*
1093	 * If sc == NULL or there are no valid disks, provider's error
1094	 * should be set and g_mirror_start() should not be called at all.
1095	 */
1096	KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1097	    ("Provider's error should be set (error=%d)(mirror=%s).",
1098	    bp->bio_to->error, bp->bio_to->name));
1099	G_MIRROR_LOGREQ(3, bp, "Request received.");
1100
1101	switch (bp->bio_cmd) {
1102	case BIO_READ:
1103	case BIO_WRITE:
1104	case BIO_DELETE:
1105		break;
1106	case BIO_FLUSH:
1107		g_mirror_flush(sc, bp);
1108		return;
1109	case BIO_GETATTR:
1110		if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1111			g_mirror_kernel_dump(bp);
1112			return;
1113		}
1114		/* FALLTHROUGH */
1115	default:
1116		g_io_deliver(bp, EOPNOTSUPP);
1117		return;
1118	}
1119	mtx_lock(&sc->sc_queue_mtx);
1120	bioq_disksort(&sc->sc_queue, bp);
1121	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1122	wakeup(sc);
1123	mtx_unlock(&sc->sc_queue_mtx);
1124}
1125
1126/*
1127 * Return TRUE if the given request is colliding with a in-progress
1128 * synchronization request.
1129 */
1130static int
1131g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1132{
1133	struct g_mirror_disk *disk;
1134	struct bio *sbp;
1135	off_t rstart, rend, sstart, send;
1136	int i;
1137
1138	if (sc->sc_sync.ds_ndisks == 0)
1139		return (0);
1140	rstart = bp->bio_offset;
1141	rend = bp->bio_offset + bp->bio_length;
1142	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1143		if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1144			continue;
1145		for (i = 0; i < g_mirror_syncreqs; i++) {
1146			sbp = disk->d_sync.ds_bios[i];
1147			if (sbp == NULL)
1148				continue;
1149			sstart = sbp->bio_offset;
1150			send = sbp->bio_offset + sbp->bio_length;
1151			if (rend > sstart && rstart < send)
1152				return (1);
1153		}
1154	}
1155	return (0);
1156}
1157
1158/*
1159 * Return TRUE if the given sync request is colliding with a in-progress regular
1160 * request.
1161 */
1162static int
1163g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1164{
1165	off_t rstart, rend, sstart, send;
1166	struct bio *bp;
1167
1168	if (sc->sc_sync.ds_ndisks == 0)
1169		return (0);
1170	sstart = sbp->bio_offset;
1171	send = sbp->bio_offset + sbp->bio_length;
1172	TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1173		rstart = bp->bio_offset;
1174		rend = bp->bio_offset + bp->bio_length;
1175		if (rend > sstart && rstart < send)
1176			return (1);
1177	}
1178	return (0);
1179}
1180
1181/*
1182 * Puts request onto delayed queue.
1183 */
1184static void
1185g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1186{
1187
1188	G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1189	bioq_insert_head(&sc->sc_regular_delayed, bp);
1190}
1191
1192/*
1193 * Puts synchronization request onto delayed queue.
1194 */
1195static void
1196g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1197{
1198
1199	G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1200	bioq_insert_tail(&sc->sc_sync_delayed, bp);
1201}
1202
1203/*
1204 * Releases delayed regular requests which don't collide anymore with sync
1205 * requests.
1206 */
1207static void
1208g_mirror_regular_release(struct g_mirror_softc *sc)
1209{
1210	struct bio *bp, *bp2;
1211
1212	TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1213		if (g_mirror_sync_collision(sc, bp))
1214			continue;
1215		bioq_remove(&sc->sc_regular_delayed, bp);
1216		G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1217		mtx_lock(&sc->sc_queue_mtx);
1218		bioq_insert_head(&sc->sc_queue, bp);
1219#if 0
1220		/*
1221		 * wakeup() is not needed, because this function is called from
1222		 * the worker thread.
1223		 */
1224		wakeup(&sc->sc_queue);
1225#endif
1226		mtx_unlock(&sc->sc_queue_mtx);
1227	}
1228}
1229
1230/*
1231 * Releases delayed sync requests which don't collide anymore with regular
1232 * requests.
1233 */
1234static void
1235g_mirror_sync_release(struct g_mirror_softc *sc)
1236{
1237	struct bio *bp, *bp2;
1238
1239	TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1240		if (g_mirror_regular_collision(sc, bp))
1241			continue;
1242		bioq_remove(&sc->sc_sync_delayed, bp);
1243		G_MIRROR_LOGREQ(2, bp,
1244		    "Releasing delayed synchronization request.");
1245		g_io_request(bp, bp->bio_from);
1246	}
1247}
1248
1249/*
1250 * Handle synchronization requests.
1251 * Every synchronization request is two-steps process: first, READ request is
1252 * send to active provider and then WRITE request (with read data) to the provider
1253 * beeing synchronized. When WRITE is finished, new synchronization request is
1254 * send.
1255 */
1256static void
1257g_mirror_sync_request(struct bio *bp)
1258{
1259	struct g_mirror_softc *sc;
1260	struct g_mirror_disk *disk;
1261
1262	bp->bio_from->index--;
1263	sc = bp->bio_from->geom->softc;
1264	disk = bp->bio_from->private;
1265	if (disk == NULL) {
1266		sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1267		g_topology_lock();
1268		g_mirror_kill_consumer(sc, bp->bio_from);
1269		g_topology_unlock();
1270		free(bp->bio_data, M_MIRROR);
1271		g_destroy_bio(bp);
1272		sx_xlock(&sc->sc_lock);
1273		return;
1274	}
1275
1276	/*
1277	 * Synchronization request.
1278	 */
1279	switch (bp->bio_cmd) {
1280	case BIO_READ:
1281	    {
1282		struct g_consumer *cp;
1283
1284		if (bp->bio_error != 0) {
1285			G_MIRROR_LOGREQ(0, bp,
1286			    "Synchronization request failed (error=%d).",
1287			    bp->bio_error);
1288			g_destroy_bio(bp);
1289			return;
1290		}
1291		G_MIRROR_LOGREQ(3, bp,
1292		    "Synchronization request half-finished.");
1293		bp->bio_cmd = BIO_WRITE;
1294		bp->bio_cflags = 0;
1295		cp = disk->d_consumer;
1296		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1297		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1298		    cp->acr, cp->acw, cp->ace));
1299		cp->index++;
1300		g_io_request(bp, cp);
1301		return;
1302	    }
1303	case BIO_WRITE:
1304	    {
1305		struct g_mirror_disk_sync *sync;
1306		off_t offset;
1307		void *data;
1308		int i;
1309
1310		if (bp->bio_error != 0) {
1311			G_MIRROR_LOGREQ(0, bp,
1312			    "Synchronization request failed (error=%d).",
1313			    bp->bio_error);
1314			g_destroy_bio(bp);
1315			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1316			g_mirror_event_send(disk,
1317			    G_MIRROR_DISK_STATE_DISCONNECTED,
1318			    G_MIRROR_EVENT_DONTWAIT);
1319			return;
1320		}
1321		G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1322		sync = &disk->d_sync;
1323		if (sync->ds_offset == sc->sc_mediasize ||
1324		    sync->ds_consumer == NULL ||
1325		    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1326			/* Don't send more synchronization requests. */
1327			sync->ds_inflight--;
1328			if (sync->ds_bios != NULL) {
1329				i = (int)(uintptr_t)bp->bio_caller1;
1330				sync->ds_bios[i] = NULL;
1331			}
1332			free(bp->bio_data, M_MIRROR);
1333			g_destroy_bio(bp);
1334			if (sync->ds_inflight > 0)
1335				return;
1336			if (sync->ds_consumer == NULL ||
1337			    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1338				return;
1339			}
1340			/* Disk up-to-date, activate it. */
1341			g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1342			    G_MIRROR_EVENT_DONTWAIT);
1343			return;
1344		}
1345
1346		/* Send next synchronization request. */
1347		data = bp->bio_data;
1348		bzero(bp, sizeof(*bp));
1349		bp->bio_cmd = BIO_READ;
1350		bp->bio_offset = sync->ds_offset;
1351		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1352		sync->ds_offset += bp->bio_length;
1353		bp->bio_done = g_mirror_sync_done;
1354		bp->bio_data = data;
1355		bp->bio_from = sync->ds_consumer;
1356		bp->bio_to = sc->sc_provider;
1357		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1358		sync->ds_consumer->index++;
1359		/*
1360		 * Delay the request if it is colliding with a regular request.
1361		 */
1362		if (g_mirror_regular_collision(sc, bp))
1363			g_mirror_sync_delay(sc, bp);
1364		else
1365			g_io_request(bp, sync->ds_consumer);
1366
1367		/* Release delayed requests if possible. */
1368		g_mirror_regular_release(sc);
1369
1370		/* Find the smallest offset */
1371		offset = sc->sc_mediasize;
1372		for (i = 0; i < g_mirror_syncreqs; i++) {
1373			bp = sync->ds_bios[i];
1374			if (bp->bio_offset < offset)
1375				offset = bp->bio_offset;
1376		}
1377		if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1378			/* Update offset_done on every 100 blocks. */
1379			sync->ds_offset_done = offset;
1380			g_mirror_update_metadata(disk);
1381		}
1382		return;
1383	    }
1384	default:
1385		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1386		    bp->bio_cmd, sc->sc_name));
1387		break;
1388	}
1389}
1390
1391static void
1392g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1393{
1394	struct g_mirror_disk *disk;
1395	struct g_consumer *cp;
1396	struct bio *cbp;
1397
1398	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1399		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1400			break;
1401	}
1402	if (disk == NULL) {
1403		if (bp->bio_error == 0)
1404			bp->bio_error = ENXIO;
1405		g_io_deliver(bp, bp->bio_error);
1406		return;
1407	}
1408	cbp = g_clone_bio(bp);
1409	if (cbp == NULL) {
1410		if (bp->bio_error == 0)
1411			bp->bio_error = ENOMEM;
1412		g_io_deliver(bp, bp->bio_error);
1413		return;
1414	}
1415	/*
1416	 * Fill in the component buf structure.
1417	 */
1418	cp = disk->d_consumer;
1419	cbp->bio_done = g_mirror_done;
1420	cbp->bio_to = cp->provider;
1421	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1422	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1423	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1424	    cp->acw, cp->ace));
1425	cp->index++;
1426	g_io_request(cbp, cp);
1427}
1428
1429static void
1430g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1431{
1432	struct g_mirror_disk *disk;
1433	struct g_consumer *cp;
1434	struct bio *cbp;
1435
1436	disk = g_mirror_get_disk(sc);
1437	if (disk == NULL) {
1438		if (bp->bio_error == 0)
1439			bp->bio_error = ENXIO;
1440		g_io_deliver(bp, bp->bio_error);
1441		return;
1442	}
1443	cbp = g_clone_bio(bp);
1444	if (cbp == NULL) {
1445		if (bp->bio_error == 0)
1446			bp->bio_error = ENOMEM;
1447		g_io_deliver(bp, bp->bio_error);
1448		return;
1449	}
1450	/*
1451	 * Fill in the component buf structure.
1452	 */
1453	cp = disk->d_consumer;
1454	cbp->bio_done = g_mirror_done;
1455	cbp->bio_to = cp->provider;
1456	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1457	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1458	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1459	    cp->acw, cp->ace));
1460	cp->index++;
1461	g_io_request(cbp, cp);
1462}
1463
1464static void
1465g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1466{
1467	struct g_mirror_disk *disk, *dp;
1468	struct g_consumer *cp;
1469	struct bio *cbp;
1470	struct bintime curtime;
1471
1472	binuptime(&curtime);
1473	/*
1474	 * Find a disk which the smallest load.
1475	 */
1476	disk = NULL;
1477	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1478		if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1479			continue;
1480		/* If disk wasn't used for more than 2 sec, use it. */
1481		if (curtime.sec - dp->d_last_used.sec >= 2) {
1482			disk = dp;
1483			break;
1484		}
1485		if (disk == NULL ||
1486		    bintime_cmp(&dp->d_delay, &disk->d_delay) < 0) {
1487			disk = dp;
1488		}
1489	}
1490	KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1491	cbp = g_clone_bio(bp);
1492	if (cbp == NULL) {
1493		if (bp->bio_error == 0)
1494			bp->bio_error = ENOMEM;
1495		g_io_deliver(bp, bp->bio_error);
1496		return;
1497	}
1498	/*
1499	 * Fill in the component buf structure.
1500	 */
1501	cp = disk->d_consumer;
1502	cbp->bio_done = g_mirror_done;
1503	cbp->bio_to = cp->provider;
1504	binuptime(&disk->d_last_used);
1505	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1506	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1507	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1508	    cp->acw, cp->ace));
1509	cp->index++;
1510	g_io_request(cbp, cp);
1511}
1512
1513static void
1514g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1515{
1516	struct bio_queue_head queue;
1517	struct g_mirror_disk *disk;
1518	struct g_consumer *cp;
1519	struct bio *cbp;
1520	off_t left, mod, offset, slice;
1521	u_char *data;
1522	u_int ndisks;
1523
1524	if (bp->bio_length <= sc->sc_slice) {
1525		g_mirror_request_round_robin(sc, bp);
1526		return;
1527	}
1528	ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1529	slice = bp->bio_length / ndisks;
1530	mod = slice % sc->sc_provider->sectorsize;
1531	if (mod != 0)
1532		slice += sc->sc_provider->sectorsize - mod;
1533	/*
1534	 * Allocate all bios before sending any request, so we can
1535	 * return ENOMEM in nice and clean way.
1536	 */
1537	left = bp->bio_length;
1538	offset = bp->bio_offset;
1539	data = bp->bio_data;
1540	bioq_init(&queue);
1541	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1542		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1543			continue;
1544		cbp = g_clone_bio(bp);
1545		if (cbp == NULL) {
1546			for (cbp = bioq_first(&queue); cbp != NULL;
1547			    cbp = bioq_first(&queue)) {
1548				bioq_remove(&queue, cbp);
1549				g_destroy_bio(cbp);
1550			}
1551			if (bp->bio_error == 0)
1552				bp->bio_error = ENOMEM;
1553			g_io_deliver(bp, bp->bio_error);
1554			return;
1555		}
1556		bioq_insert_tail(&queue, cbp);
1557		cbp->bio_done = g_mirror_done;
1558		cbp->bio_caller1 = disk;
1559		cbp->bio_to = disk->d_consumer->provider;
1560		cbp->bio_offset = offset;
1561		cbp->bio_data = data;
1562		cbp->bio_length = MIN(left, slice);
1563		left -= cbp->bio_length;
1564		if (left == 0)
1565			break;
1566		offset += cbp->bio_length;
1567		data += cbp->bio_length;
1568	}
1569	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1570		bioq_remove(&queue, cbp);
1571		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1572		disk = cbp->bio_caller1;
1573		cbp->bio_caller1 = NULL;
1574		cp = disk->d_consumer;
1575		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1576		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1577		    cp->acr, cp->acw, cp->ace));
1578		disk->d_consumer->index++;
1579		g_io_request(cbp, disk->d_consumer);
1580	}
1581}
1582
1583static void
1584g_mirror_register_request(struct bio *bp)
1585{
1586	struct g_mirror_softc *sc;
1587
1588	sc = bp->bio_to->geom->softc;
1589	switch (bp->bio_cmd) {
1590	case BIO_READ:
1591		switch (sc->sc_balance) {
1592		case G_MIRROR_BALANCE_LOAD:
1593			g_mirror_request_load(sc, bp);
1594			break;
1595		case G_MIRROR_BALANCE_PREFER:
1596			g_mirror_request_prefer(sc, bp);
1597			break;
1598		case G_MIRROR_BALANCE_ROUND_ROBIN:
1599			g_mirror_request_round_robin(sc, bp);
1600			break;
1601		case G_MIRROR_BALANCE_SPLIT:
1602			g_mirror_request_split(sc, bp);
1603			break;
1604		}
1605		return;
1606	case BIO_WRITE:
1607	case BIO_DELETE:
1608	    {
1609		struct g_mirror_disk *disk;
1610		struct g_mirror_disk_sync *sync;
1611		struct bio_queue_head queue;
1612		struct g_consumer *cp;
1613		struct bio *cbp;
1614
1615		/*
1616		 * Delay the request if it is colliding with a synchronization
1617		 * request.
1618		 */
1619		if (g_mirror_sync_collision(sc, bp)) {
1620			g_mirror_regular_delay(sc, bp);
1621			return;
1622		}
1623
1624		if (sc->sc_idle)
1625			g_mirror_unidle(sc);
1626		else
1627			sc->sc_last_write = time_uptime;
1628
1629		/*
1630		 * Allocate all bios before sending any request, so we can
1631		 * return ENOMEM in nice and clean way.
1632		 */
1633		bioq_init(&queue);
1634		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1635			sync = &disk->d_sync;
1636			switch (disk->d_state) {
1637			case G_MIRROR_DISK_STATE_ACTIVE:
1638				break;
1639			case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1640				if (bp->bio_offset >= sync->ds_offset)
1641					continue;
1642				break;
1643			default:
1644				continue;
1645			}
1646			cbp = g_clone_bio(bp);
1647			if (cbp == NULL) {
1648				for (cbp = bioq_first(&queue); cbp != NULL;
1649				    cbp = bioq_first(&queue)) {
1650					bioq_remove(&queue, cbp);
1651					g_destroy_bio(cbp);
1652				}
1653				if (bp->bio_error == 0)
1654					bp->bio_error = ENOMEM;
1655				g_io_deliver(bp, bp->bio_error);
1656				return;
1657			}
1658			bioq_insert_tail(&queue, cbp);
1659			cbp->bio_done = g_mirror_done;
1660			cp = disk->d_consumer;
1661			cbp->bio_caller1 = cp;
1662			cbp->bio_to = cp->provider;
1663			KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1664			    ("Consumer %s not opened (r%dw%de%d).",
1665			    cp->provider->name, cp->acr, cp->acw, cp->ace));
1666		}
1667		for (cbp = bioq_first(&queue); cbp != NULL;
1668		    cbp = bioq_first(&queue)) {
1669			bioq_remove(&queue, cbp);
1670			G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1671			cp = cbp->bio_caller1;
1672			cbp->bio_caller1 = NULL;
1673			cp->index++;
1674			sc->sc_writes++;
1675			g_io_request(cbp, cp);
1676		}
1677		/*
1678		 * Put request onto inflight queue, so we can check if new
1679		 * synchronization requests don't collide with it.
1680		 */
1681		bioq_insert_tail(&sc->sc_inflight, bp);
1682		/*
1683		 * Bump syncid on first write.
1684		 */
1685		if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1686			sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1687			g_mirror_bump_syncid(sc);
1688		}
1689		return;
1690	    }
1691	default:
1692		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1693		    bp->bio_cmd, sc->sc_name));
1694		break;
1695	}
1696}
1697
1698static int
1699g_mirror_can_destroy(struct g_mirror_softc *sc)
1700{
1701	struct g_geom *gp;
1702	struct g_consumer *cp;
1703
1704	g_topology_assert();
1705	gp = sc->sc_geom;
1706	if (gp->softc == NULL)
1707		return (1);
1708	LIST_FOREACH(cp, &gp->consumer, consumer) {
1709		if (g_mirror_is_busy(sc, cp))
1710			return (0);
1711	}
1712	gp = sc->sc_sync.ds_geom;
1713	LIST_FOREACH(cp, &gp->consumer, consumer) {
1714		if (g_mirror_is_busy(sc, cp))
1715			return (0);
1716	}
1717	G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1718	    sc->sc_name);
1719	return (1);
1720}
1721
1722static int
1723g_mirror_try_destroy(struct g_mirror_softc *sc)
1724{
1725
1726	if (sc->sc_rootmount != NULL) {
1727		G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1728		    sc->sc_rootmount);
1729		root_mount_rel(sc->sc_rootmount);
1730		sc->sc_rootmount = NULL;
1731	}
1732	g_topology_lock();
1733	if (!g_mirror_can_destroy(sc)) {
1734		g_topology_unlock();
1735		return (0);
1736	}
1737	sc->sc_geom->softc = NULL;
1738	sc->sc_sync.ds_geom->softc = NULL;
1739	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WAIT) != 0) {
1740		g_topology_unlock();
1741		G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1742		    &sc->sc_worker);
1743		/* Unlock sc_lock here, as it can be destroyed after wakeup. */
1744		sx_xunlock(&sc->sc_lock);
1745		wakeup(&sc->sc_worker);
1746		sc->sc_worker = NULL;
1747	} else {
1748		g_topology_unlock();
1749		g_mirror_destroy_device(sc);
1750		free(sc, M_MIRROR);
1751	}
1752	return (1);
1753}
1754
1755/*
1756 * Worker thread.
1757 */
1758static void
1759g_mirror_worker(void *arg)
1760{
1761	struct g_mirror_softc *sc;
1762	struct g_mirror_event *ep;
1763	struct bio *bp;
1764	int timeout;
1765
1766	sc = arg;
1767	mtx_lock_spin(&sched_lock);
1768	sched_prio(curthread, PRIBIO);
1769	mtx_unlock_spin(&sched_lock);
1770
1771	sx_xlock(&sc->sc_lock);
1772	for (;;) {
1773		G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1774		/*
1775		 * First take a look at events.
1776		 * This is important to handle events before any I/O requests.
1777		 */
1778		ep = g_mirror_event_get(sc);
1779		if (ep != NULL) {
1780			g_mirror_event_remove(sc, ep);
1781			if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1782				/* Update only device status. */
1783				G_MIRROR_DEBUG(3,
1784				    "Running event for device %s.",
1785				    sc->sc_name);
1786				ep->e_error = 0;
1787				g_mirror_update_device(sc, 1);
1788			} else {
1789				/* Update disk status. */
1790				G_MIRROR_DEBUG(3, "Running event for disk %s.",
1791				     g_mirror_get_diskname(ep->e_disk));
1792				ep->e_error = g_mirror_update_disk(ep->e_disk,
1793				    ep->e_state);
1794				if (ep->e_error == 0)
1795					g_mirror_update_device(sc, 0);
1796			}
1797			if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1798				KASSERT(ep->e_error == 0,
1799				    ("Error cannot be handled."));
1800				g_mirror_event_free(ep);
1801			} else {
1802				ep->e_flags |= G_MIRROR_EVENT_DONE;
1803				G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1804				    ep);
1805				mtx_lock(&sc->sc_events_mtx);
1806				wakeup(ep);
1807				mtx_unlock(&sc->sc_events_mtx);
1808			}
1809			if ((sc->sc_flags &
1810			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1811				if (g_mirror_try_destroy(sc)) {
1812					curthread->td_pflags &= ~TDP_GEOM;
1813					G_MIRROR_DEBUG(1, "Thread exiting.");
1814					kthread_exit(0);
1815				}
1816			}
1817			G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1818			continue;
1819		}
1820		/*
1821		 * Check if we can mark array as CLEAN and if we can't take
1822		 * how much seconds should we wait.
1823		 */
1824		timeout = g_mirror_idle(sc, -1);
1825		/*
1826		 * Now I/O requests.
1827		 */
1828		/* Get first request from the queue. */
1829		mtx_lock(&sc->sc_queue_mtx);
1830		bp = bioq_first(&sc->sc_queue);
1831		if (bp == NULL) {
1832			if ((sc->sc_flags &
1833			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1834				mtx_unlock(&sc->sc_queue_mtx);
1835				if (g_mirror_try_destroy(sc)) {
1836					curthread->td_pflags &= ~TDP_GEOM;
1837					G_MIRROR_DEBUG(1, "Thread exiting.");
1838					kthread_exit(0);
1839				}
1840				mtx_lock(&sc->sc_queue_mtx);
1841			}
1842			sx_xunlock(&sc->sc_lock);
1843			/*
1844			 * XXX: We can miss an event here, because an event
1845			 *      can be added without sx-device-lock and without
1846			 *      mtx-queue-lock. Maybe I should just stop using
1847			 *      dedicated mutex for events synchronization and
1848			 *      stick with the queue lock?
1849			 *      The event will hang here until next I/O request
1850			 *      or next event is received.
1851			 */
1852			MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1853			    timeout * hz);
1854			sx_xlock(&sc->sc_lock);
1855			G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1856			continue;
1857		}
1858		bioq_remove(&sc->sc_queue, bp);
1859		mtx_unlock(&sc->sc_queue_mtx);
1860
1861		if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1862		    (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1863			g_mirror_sync_request(bp);	/* READ */
1864		} else if (bp->bio_to != sc->sc_provider) {
1865			if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1866				g_mirror_regular_request(bp);
1867			else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1868				g_mirror_sync_request(bp);	/* WRITE */
1869			else {
1870				KASSERT(0,
1871				    ("Invalid request cflags=0x%hhx to=%s.",
1872				    bp->bio_cflags, bp->bio_to->name));
1873			}
1874		} else {
1875			g_mirror_register_request(bp);
1876		}
1877		G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1878	}
1879}
1880
1881static void
1882g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1883{
1884
1885	sx_assert(&sc->sc_lock, SX_LOCKED);
1886
1887	if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1888		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
1889		    g_mirror_get_diskname(disk), sc->sc_name);
1890		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1891	} else if (sc->sc_idle &&
1892	    (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1893		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
1894		    g_mirror_get_diskname(disk), sc->sc_name);
1895		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1896	}
1897}
1898
1899static void
1900g_mirror_sync_start(struct g_mirror_disk *disk)
1901{
1902	struct g_mirror_softc *sc;
1903	struct g_consumer *cp;
1904	struct bio *bp;
1905	int error, i;
1906
1907	g_topology_assert_not();
1908	sc = disk->d_softc;
1909	sx_assert(&sc->sc_lock, SX_LOCKED);
1910
1911	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1912	    ("Disk %s is not marked for synchronization.",
1913	    g_mirror_get_diskname(disk)));
1914	KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1915	    ("Device not in RUNNING state (%s, %u).", sc->sc_name,
1916	    sc->sc_state));
1917
1918	sx_xunlock(&sc->sc_lock);
1919	g_topology_lock();
1920	cp = g_new_consumer(sc->sc_sync.ds_geom);
1921	error = g_attach(cp, sc->sc_provider);
1922	KASSERT(error == 0,
1923	    ("Cannot attach to %s (error=%d).", sc->sc_name, error));
1924	error = g_access(cp, 1, 0, 0);
1925	KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
1926	g_topology_unlock();
1927	sx_xlock(&sc->sc_lock);
1928
1929	G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
1930	    g_mirror_get_diskname(disk));
1931	disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1932	KASSERT(disk->d_sync.ds_consumer == NULL,
1933	    ("Sync consumer already exists (device=%s, disk=%s).",
1934	    sc->sc_name, g_mirror_get_diskname(disk)));
1935
1936	disk->d_sync.ds_consumer = cp;
1937	disk->d_sync.ds_consumer->private = disk;
1938	disk->d_sync.ds_consumer->index = 0;
1939
1940	/*
1941	 * Allocate memory for synchronization bios and initialize them.
1942	 */
1943	disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
1944	    M_MIRROR, M_WAITOK);
1945	for (i = 0; i < g_mirror_syncreqs; i++) {
1946		bp = g_alloc_bio();
1947		disk->d_sync.ds_bios[i] = bp;
1948		bp->bio_parent = NULL;
1949		bp->bio_cmd = BIO_READ;
1950		bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
1951		bp->bio_cflags = 0;
1952		bp->bio_offset = disk->d_sync.ds_offset;
1953		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1954		disk->d_sync.ds_offset += bp->bio_length;
1955		bp->bio_done = g_mirror_sync_done;
1956		bp->bio_from = disk->d_sync.ds_consumer;
1957		bp->bio_to = sc->sc_provider;
1958		bp->bio_caller1 = (void *)(uintptr_t)i;
1959	}
1960
1961	/* Increase the number of disks in SYNCHRONIZING state. */
1962	sc->sc_sync.ds_ndisks++;
1963	/* Set the number of in-flight synchronization requests. */
1964	disk->d_sync.ds_inflight = g_mirror_syncreqs;
1965
1966	/*
1967	 * Fire off first synchronization requests.
1968	 */
1969	for (i = 0; i < g_mirror_syncreqs; i++) {
1970		bp = disk->d_sync.ds_bios[i];
1971		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1972		disk->d_sync.ds_consumer->index++;
1973		/*
1974		 * Delay the request if it is colliding with a regular request.
1975		 */
1976		if (g_mirror_regular_collision(sc, bp))
1977			g_mirror_sync_delay(sc, bp);
1978		else
1979			g_io_request(bp, disk->d_sync.ds_consumer);
1980	}
1981}
1982
1983/*
1984 * Stop synchronization process.
1985 * type: 0 - synchronization finished
1986 *       1 - synchronization stopped
1987 */
1988static void
1989g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
1990{
1991	struct g_mirror_softc *sc;
1992	struct g_consumer *cp;
1993
1994	g_topology_assert_not();
1995	sc = disk->d_softc;
1996	sx_assert(&sc->sc_lock, SX_LOCKED);
1997
1998	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1999	    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2000	    g_mirror_disk_state2str(disk->d_state)));
2001	if (disk->d_sync.ds_consumer == NULL)
2002		return;
2003
2004	if (type == 0) {
2005		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2006		    sc->sc_name, g_mirror_get_diskname(disk));
2007	} else /* if (type == 1) */ {
2008		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2009		    sc->sc_name, g_mirror_get_diskname(disk));
2010	}
2011	free(disk->d_sync.ds_bios, M_MIRROR);
2012	disk->d_sync.ds_bios = NULL;
2013	cp = disk->d_sync.ds_consumer;
2014	disk->d_sync.ds_consumer = NULL;
2015	disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2016	sc->sc_sync.ds_ndisks--;
2017	sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2018	g_topology_lock();
2019	g_mirror_kill_consumer(sc, cp);
2020	g_topology_unlock();
2021	sx_xlock(&sc->sc_lock);
2022}
2023
2024static void
2025g_mirror_launch_provider(struct g_mirror_softc *sc)
2026{
2027	struct g_mirror_disk *disk;
2028	struct g_provider *pp;
2029
2030	sx_assert(&sc->sc_lock, SX_LOCKED);
2031
2032	g_topology_lock();
2033	pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2034	pp->mediasize = sc->sc_mediasize;
2035	pp->sectorsize = sc->sc_sectorsize;
2036	sc->sc_provider = pp;
2037	g_error_provider(pp, 0);
2038	g_topology_unlock();
2039	G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2040	    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2041	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2042		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2043			g_mirror_sync_start(disk);
2044	}
2045}
2046
2047static void
2048g_mirror_destroy_provider(struct g_mirror_softc *sc)
2049{
2050	struct g_mirror_disk *disk;
2051	struct bio *bp;
2052
2053	g_topology_assert_not();
2054	KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2055	    sc->sc_name));
2056
2057	g_topology_lock();
2058	g_error_provider(sc->sc_provider, ENXIO);
2059	mtx_lock(&sc->sc_queue_mtx);
2060	while ((bp = bioq_first(&sc->sc_queue)) != NULL) {
2061		bioq_remove(&sc->sc_queue, bp);
2062		g_io_deliver(bp, ENXIO);
2063	}
2064	mtx_unlock(&sc->sc_queue_mtx);
2065	G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.", sc->sc_name,
2066	    sc->sc_provider->name);
2067	sc->sc_provider->flags |= G_PF_WITHER;
2068	g_orphan_provider(sc->sc_provider, ENXIO);
2069	g_topology_unlock();
2070	sc->sc_provider = NULL;
2071	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2072		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2073			g_mirror_sync_stop(disk, 1);
2074	}
2075}
2076
2077static void
2078g_mirror_go(void *arg)
2079{
2080	struct g_mirror_softc *sc;
2081
2082	sc = arg;
2083	G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2084	g_mirror_event_send(sc, 0,
2085	    G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2086}
2087
2088static u_int
2089g_mirror_determine_state(struct g_mirror_disk *disk)
2090{
2091	struct g_mirror_softc *sc;
2092	u_int state;
2093
2094	sc = disk->d_softc;
2095	if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2096		if ((disk->d_flags &
2097		    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2098			/* Disk does not need synchronization. */
2099			state = G_MIRROR_DISK_STATE_ACTIVE;
2100		} else {
2101			if ((sc->sc_flags &
2102			     G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2103			    (disk->d_flags &
2104			     G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2105				/*
2106				 * We can start synchronization from
2107				 * the stored offset.
2108				 */
2109				state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2110			} else {
2111				state = G_MIRROR_DISK_STATE_STALE;
2112			}
2113		}
2114	} else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2115		/*
2116		 * Reset all synchronization data for this disk,
2117		 * because if it even was synchronized, it was
2118		 * synchronized to disks with different syncid.
2119		 */
2120		disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2121		disk->d_sync.ds_offset = 0;
2122		disk->d_sync.ds_offset_done = 0;
2123		disk->d_sync.ds_syncid = sc->sc_syncid;
2124		if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2125		    (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2126			state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2127		} else {
2128			state = G_MIRROR_DISK_STATE_STALE;
2129		}
2130	} else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2131		/*
2132		 * Not good, NOT GOOD!
2133		 * It means that mirror was started on stale disks
2134		 * and more fresh disk just arrive.
2135		 * If there were writes, mirror is broken, sorry.
2136		 * I think the best choice here is don't touch
2137		 * this disk and inform the user loudly.
2138		 */
2139		G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2140		    "disk (%s) arrives!! It will not be connected to the "
2141		    "running device.", sc->sc_name,
2142		    g_mirror_get_diskname(disk));
2143		g_mirror_destroy_disk(disk);
2144		state = G_MIRROR_DISK_STATE_NONE;
2145		/* Return immediately, because disk was destroyed. */
2146		return (state);
2147	}
2148	G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2149	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2150	return (state);
2151}
2152
2153/*
2154 * Update device state.
2155 */
2156static void
2157g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force)
2158{
2159	struct g_mirror_disk *disk;
2160	u_int state;
2161
2162	sx_assert(&sc->sc_lock, SX_XLOCKED);
2163
2164	switch (sc->sc_state) {
2165	case G_MIRROR_DEVICE_STATE_STARTING:
2166	    {
2167		struct g_mirror_disk *pdisk, *tdisk;
2168		u_int dirty, ndisks, genid, syncid;
2169
2170		KASSERT(sc->sc_provider == NULL,
2171		    ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2172		/*
2173		 * Are we ready? We are, if all disks are connected or
2174		 * if we have any disks and 'force' is true.
2175		 */
2176		ndisks = g_mirror_ndisks(sc, -1);
2177		if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2178			;
2179		} else if (ndisks == 0) {
2180			/*
2181			 * Disks went down in starting phase, so destroy
2182			 * device.
2183			 */
2184			callout_drain(&sc->sc_callout);
2185			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2186			G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2187			    sc->sc_rootmount);
2188			root_mount_rel(sc->sc_rootmount);
2189			sc->sc_rootmount = NULL;
2190			return;
2191		} else {
2192			return;
2193		}
2194
2195		/*
2196		 * Activate all disks with the biggest syncid.
2197		 */
2198		if (force) {
2199			/*
2200			 * If 'force' is true, we have been called due to
2201			 * timeout, so don't bother canceling timeout.
2202			 */
2203			ndisks = 0;
2204			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2205				if ((disk->d_flags &
2206				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2207					ndisks++;
2208				}
2209			}
2210			if (ndisks == 0) {
2211				/* No valid disks found, destroy device. */
2212				sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2213				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2214				    __LINE__, sc->sc_rootmount);
2215				root_mount_rel(sc->sc_rootmount);
2216				sc->sc_rootmount = NULL;
2217				return;
2218			}
2219		} else {
2220			/* Cancel timeout. */
2221			callout_drain(&sc->sc_callout);
2222		}
2223
2224		/*
2225		 * Find the biggest genid.
2226		 */
2227		genid = 0;
2228		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2229			if (disk->d_genid > genid)
2230				genid = disk->d_genid;
2231		}
2232		sc->sc_genid = genid;
2233		/*
2234		 * Remove all disks without the biggest genid.
2235		 */
2236		LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2237			if (disk->d_genid < genid) {
2238				G_MIRROR_DEBUG(0,
2239				    "Component %s (device %s) broken, skipping.",
2240				    g_mirror_get_diskname(disk), sc->sc_name);
2241				g_mirror_destroy_disk(disk);
2242			}
2243		}
2244
2245		/*
2246		 * Find the biggest syncid.
2247		 */
2248		syncid = 0;
2249		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2250			if (disk->d_sync.ds_syncid > syncid)
2251				syncid = disk->d_sync.ds_syncid;
2252		}
2253
2254		/*
2255		 * Here we need to look for dirty disks and if all disks
2256		 * with the biggest syncid are dirty, we have to choose
2257		 * one with the biggest priority and rebuild the rest.
2258		 */
2259		/*
2260		 * Find the number of dirty disks with the biggest syncid.
2261		 * Find the number of disks with the biggest syncid.
2262		 * While here, find a disk with the biggest priority.
2263		 */
2264		dirty = ndisks = 0;
2265		pdisk = NULL;
2266		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2267			if (disk->d_sync.ds_syncid != syncid)
2268				continue;
2269			if ((disk->d_flags &
2270			    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2271				continue;
2272			}
2273			ndisks++;
2274			if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2275				dirty++;
2276				if (pdisk == NULL ||
2277				    pdisk->d_priority < disk->d_priority) {
2278					pdisk = disk;
2279				}
2280			}
2281		}
2282		if (dirty == 0) {
2283			/* No dirty disks at all, great. */
2284		} else if (dirty == ndisks) {
2285			/*
2286			 * Force synchronization for all dirty disks except one
2287			 * with the biggest priority.
2288			 */
2289			KASSERT(pdisk != NULL, ("pdisk == NULL"));
2290			G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2291			    "master disk for synchronization.",
2292			    g_mirror_get_diskname(pdisk), sc->sc_name);
2293			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2294				if (disk->d_sync.ds_syncid != syncid)
2295					continue;
2296				if ((disk->d_flags &
2297				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2298					continue;
2299				}
2300				KASSERT((disk->d_flags &
2301				    G_MIRROR_DISK_FLAG_DIRTY) != 0,
2302				    ("Disk %s isn't marked as dirty.",
2303				    g_mirror_get_diskname(disk)));
2304				/* Skip the disk with the biggest priority. */
2305				if (disk == pdisk)
2306					continue;
2307				disk->d_sync.ds_syncid = 0;
2308			}
2309		} else if (dirty < ndisks) {
2310			/*
2311			 * Force synchronization for all dirty disks.
2312			 * We have some non-dirty disks.
2313			 */
2314			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2315				if (disk->d_sync.ds_syncid != syncid)
2316					continue;
2317				if ((disk->d_flags &
2318				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2319					continue;
2320				}
2321				if ((disk->d_flags &
2322				    G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2323					continue;
2324				}
2325				disk->d_sync.ds_syncid = 0;
2326			}
2327		}
2328
2329		/* Reset hint. */
2330		sc->sc_hint = NULL;
2331		sc->sc_syncid = syncid;
2332		if (force) {
2333			/* Remember to bump syncid on first write. */
2334			sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2335		}
2336		state = G_MIRROR_DEVICE_STATE_RUNNING;
2337		G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2338		    sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2339		    g_mirror_device_state2str(state));
2340		sc->sc_state = state;
2341		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2342			state = g_mirror_determine_state(disk);
2343			g_mirror_event_send(disk, state,
2344			    G_MIRROR_EVENT_DONTWAIT);
2345			if (state == G_MIRROR_DISK_STATE_STALE)
2346				sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2347		}
2348		break;
2349	    }
2350	case G_MIRROR_DEVICE_STATE_RUNNING:
2351		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2352		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2353			/*
2354			 * No active disks or no disks at all,
2355			 * so destroy device.
2356			 */
2357			if (sc->sc_provider != NULL)
2358				g_mirror_destroy_provider(sc);
2359			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2360			break;
2361		} else if (g_mirror_ndisks(sc,
2362		    G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2363		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2364			/*
2365			 * We have active disks, launch provider if it doesn't
2366			 * exist.
2367			 */
2368			if (sc->sc_provider == NULL)
2369				g_mirror_launch_provider(sc);
2370			if (sc->sc_rootmount != NULL) {
2371				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2372				    __LINE__, sc->sc_rootmount);
2373				root_mount_rel(sc->sc_rootmount);
2374				sc->sc_rootmount = NULL;
2375			}
2376		}
2377		/*
2378		 * Genid should be bumped immediately, so do it here.
2379		 */
2380		if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2381			sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2382			g_mirror_bump_genid(sc);
2383		}
2384		break;
2385	default:
2386		KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2387		    sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2388		break;
2389	}
2390}
2391
2392/*
2393 * Update disk state and device state if needed.
2394 */
2395#define	DISK_STATE_CHANGED()	G_MIRROR_DEBUG(1,			\
2396	"Disk %s state changed from %s to %s (device %s).",		\
2397	g_mirror_get_diskname(disk),					\
2398	g_mirror_disk_state2str(disk->d_state),				\
2399	g_mirror_disk_state2str(state), sc->sc_name)
2400static int
2401g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2402{
2403	struct g_mirror_softc *sc;
2404
2405	sc = disk->d_softc;
2406	sx_assert(&sc->sc_lock, SX_XLOCKED);
2407
2408again:
2409	G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2410	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2411	    g_mirror_disk_state2str(state));
2412	switch (state) {
2413	case G_MIRROR_DISK_STATE_NEW:
2414		/*
2415		 * Possible scenarios:
2416		 * 1. New disk arrive.
2417		 */
2418		/* Previous state should be NONE. */
2419		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2420		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2421		    g_mirror_disk_state2str(disk->d_state)));
2422		DISK_STATE_CHANGED();
2423
2424		disk->d_state = state;
2425		if (LIST_EMPTY(&sc->sc_disks))
2426			LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2427		else {
2428			struct g_mirror_disk *dp;
2429
2430			LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2431				if (disk->d_priority >= dp->d_priority) {
2432					LIST_INSERT_BEFORE(dp, disk, d_next);
2433					dp = NULL;
2434					break;
2435				}
2436				if (LIST_NEXT(dp, d_next) == NULL)
2437					break;
2438			}
2439			if (dp != NULL)
2440				LIST_INSERT_AFTER(dp, disk, d_next);
2441		}
2442		G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2443		    sc->sc_name, g_mirror_get_diskname(disk));
2444		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2445			break;
2446		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2447		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2448		    g_mirror_device_state2str(sc->sc_state),
2449		    g_mirror_get_diskname(disk),
2450		    g_mirror_disk_state2str(disk->d_state)));
2451		state = g_mirror_determine_state(disk);
2452		if (state != G_MIRROR_DISK_STATE_NONE)
2453			goto again;
2454		break;
2455	case G_MIRROR_DISK_STATE_ACTIVE:
2456		/*
2457		 * Possible scenarios:
2458		 * 1. New disk does not need synchronization.
2459		 * 2. Synchronization process finished successfully.
2460		 */
2461		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2462		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2463		    g_mirror_device_state2str(sc->sc_state),
2464		    g_mirror_get_diskname(disk),
2465		    g_mirror_disk_state2str(disk->d_state)));
2466		/* Previous state should be NEW or SYNCHRONIZING. */
2467		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2468		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2469		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2470		    g_mirror_disk_state2str(disk->d_state)));
2471		DISK_STATE_CHANGED();
2472
2473		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2474			disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2475			disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2476			g_mirror_sync_stop(disk, 0);
2477		}
2478		disk->d_state = state;
2479		disk->d_sync.ds_offset = 0;
2480		disk->d_sync.ds_offset_done = 0;
2481		g_mirror_update_idle(sc, disk);
2482		g_mirror_update_metadata(disk);
2483		G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2484		    sc->sc_name, g_mirror_get_diskname(disk));
2485		break;
2486	case G_MIRROR_DISK_STATE_STALE:
2487		/*
2488		 * Possible scenarios:
2489		 * 1. Stale disk was connected.
2490		 */
2491		/* Previous state should be NEW. */
2492		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2493		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2494		    g_mirror_disk_state2str(disk->d_state)));
2495		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2496		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2497		    g_mirror_device_state2str(sc->sc_state),
2498		    g_mirror_get_diskname(disk),
2499		    g_mirror_disk_state2str(disk->d_state)));
2500		/*
2501		 * STALE state is only possible if device is marked
2502		 * NOAUTOSYNC.
2503		 */
2504		KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2505		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2506		    g_mirror_device_state2str(sc->sc_state),
2507		    g_mirror_get_diskname(disk),
2508		    g_mirror_disk_state2str(disk->d_state)));
2509		DISK_STATE_CHANGED();
2510
2511		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2512		disk->d_state = state;
2513		g_mirror_update_metadata(disk);
2514		G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2515		    sc->sc_name, g_mirror_get_diskname(disk));
2516		break;
2517	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2518		/*
2519		 * Possible scenarios:
2520		 * 1. Disk which needs synchronization was connected.
2521		 */
2522		/* Previous state should be NEW. */
2523		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2524		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2525		    g_mirror_disk_state2str(disk->d_state)));
2526		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2527		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2528		    g_mirror_device_state2str(sc->sc_state),
2529		    g_mirror_get_diskname(disk),
2530		    g_mirror_disk_state2str(disk->d_state)));
2531		DISK_STATE_CHANGED();
2532
2533		if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2534			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2535		disk->d_state = state;
2536		if (sc->sc_provider != NULL) {
2537			g_mirror_sync_start(disk);
2538			g_mirror_update_metadata(disk);
2539		}
2540		break;
2541	case G_MIRROR_DISK_STATE_DISCONNECTED:
2542		/*
2543		 * Possible scenarios:
2544		 * 1. Device wasn't running yet, but disk disappear.
2545		 * 2. Disk was active and disapppear.
2546		 * 3. Disk disappear during synchronization process.
2547		 */
2548		if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2549			/*
2550			 * Previous state should be ACTIVE, STALE or
2551			 * SYNCHRONIZING.
2552			 */
2553			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2554			    disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2555			    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2556			    ("Wrong disk state (%s, %s).",
2557			    g_mirror_get_diskname(disk),
2558			    g_mirror_disk_state2str(disk->d_state)));
2559		} else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2560			/* Previous state should be NEW. */
2561			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2562			    ("Wrong disk state (%s, %s).",
2563			    g_mirror_get_diskname(disk),
2564			    g_mirror_disk_state2str(disk->d_state)));
2565			/*
2566			 * Reset bumping syncid if disk disappeared in STARTING
2567			 * state.
2568			 */
2569			if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2570				sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2571#ifdef	INVARIANTS
2572		} else {
2573			KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2574			    sc->sc_name,
2575			    g_mirror_device_state2str(sc->sc_state),
2576			    g_mirror_get_diskname(disk),
2577			    g_mirror_disk_state2str(disk->d_state)));
2578#endif
2579		}
2580		DISK_STATE_CHANGED();
2581		G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2582		    sc->sc_name, g_mirror_get_diskname(disk));
2583
2584		g_mirror_destroy_disk(disk);
2585		break;
2586	case G_MIRROR_DISK_STATE_DESTROY:
2587	    {
2588		int error;
2589
2590		error = g_mirror_clear_metadata(disk);
2591		if (error != 0)
2592			return (error);
2593		DISK_STATE_CHANGED();
2594		G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2595		    sc->sc_name, g_mirror_get_diskname(disk));
2596
2597		g_mirror_destroy_disk(disk);
2598		sc->sc_ndisks--;
2599		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2600			g_mirror_update_metadata(disk);
2601		}
2602		break;
2603	    }
2604	default:
2605		KASSERT(1 == 0, ("Unknown state (%u).", state));
2606		break;
2607	}
2608	return (0);
2609}
2610#undef	DISK_STATE_CHANGED
2611
2612int
2613g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2614{
2615	struct g_provider *pp;
2616	u_char *buf;
2617	int error;
2618
2619	g_topology_assert();
2620
2621	error = g_access(cp, 1, 0, 0);
2622	if (error != 0)
2623		return (error);
2624	pp = cp->provider;
2625	g_topology_unlock();
2626	/* Metadata are stored on last sector. */
2627	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2628	    &error);
2629	g_topology_lock();
2630	g_access(cp, -1, 0, 0);
2631	if (buf == NULL) {
2632		G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2633		    cp->provider->name, error);
2634		return (error);
2635	}
2636
2637	/* Decode metadata. */
2638	error = mirror_metadata_decode(buf, md);
2639	g_free(buf);
2640	if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2641		return (EINVAL);
2642	if (md->md_version > G_MIRROR_VERSION) {
2643		G_MIRROR_DEBUG(0,
2644		    "Kernel module is too old to handle metadata from %s.",
2645		    cp->provider->name);
2646		return (EINVAL);
2647	}
2648	if (error != 0) {
2649		G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2650		    cp->provider->name);
2651		return (error);
2652	}
2653
2654	return (0);
2655}
2656
2657static int
2658g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2659    struct g_mirror_metadata *md)
2660{
2661
2662	if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2663		G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2664		    pp->name, md->md_did);
2665		return (EEXIST);
2666	}
2667	if (md->md_all != sc->sc_ndisks) {
2668		G_MIRROR_DEBUG(1,
2669		    "Invalid '%s' field on disk %s (device %s), skipping.",
2670		    "md_all", pp->name, sc->sc_name);
2671		return (EINVAL);
2672	}
2673	if (md->md_slice != sc->sc_slice) {
2674		G_MIRROR_DEBUG(1,
2675		    "Invalid '%s' field on disk %s (device %s), skipping.",
2676		    "md_slice", pp->name, sc->sc_name);
2677		return (EINVAL);
2678	}
2679	if (md->md_balance != sc->sc_balance) {
2680		G_MIRROR_DEBUG(1,
2681		    "Invalid '%s' field on disk %s (device %s), skipping.",
2682		    "md_balance", pp->name, sc->sc_name);
2683		return (EINVAL);
2684	}
2685	if (md->md_mediasize != sc->sc_mediasize) {
2686		G_MIRROR_DEBUG(1,
2687		    "Invalid '%s' field on disk %s (device %s), skipping.",
2688		    "md_mediasize", pp->name, sc->sc_name);
2689		return (EINVAL);
2690	}
2691	if (sc->sc_mediasize > pp->mediasize) {
2692		G_MIRROR_DEBUG(1,
2693		    "Invalid size of disk %s (device %s), skipping.", pp->name,
2694		    sc->sc_name);
2695		return (EINVAL);
2696	}
2697	if (md->md_sectorsize != sc->sc_sectorsize) {
2698		G_MIRROR_DEBUG(1,
2699		    "Invalid '%s' field on disk %s (device %s), skipping.",
2700		    "md_sectorsize", pp->name, sc->sc_name);
2701		return (EINVAL);
2702	}
2703	if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2704		G_MIRROR_DEBUG(1,
2705		    "Invalid sector size of disk %s (device %s), skipping.",
2706		    pp->name, sc->sc_name);
2707		return (EINVAL);
2708	}
2709	if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2710		G_MIRROR_DEBUG(1,
2711		    "Invalid device flags on disk %s (device %s), skipping.",
2712		    pp->name, sc->sc_name);
2713		return (EINVAL);
2714	}
2715	if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2716		G_MIRROR_DEBUG(1,
2717		    "Invalid disk flags on disk %s (device %s), skipping.",
2718		    pp->name, sc->sc_name);
2719		return (EINVAL);
2720	}
2721	return (0);
2722}
2723
2724int
2725g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2726    struct g_mirror_metadata *md)
2727{
2728	struct g_mirror_disk *disk;
2729	int error;
2730
2731	g_topology_assert_not();
2732	G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2733
2734	error = g_mirror_check_metadata(sc, pp, md);
2735	if (error != 0)
2736		return (error);
2737	if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2738	    md->md_genid < sc->sc_genid) {
2739		G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2740		    pp->name, sc->sc_name);
2741		return (EINVAL);
2742	}
2743	disk = g_mirror_init_disk(sc, pp, md, &error);
2744	if (disk == NULL)
2745		return (error);
2746	error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2747	    G_MIRROR_EVENT_WAIT);
2748	if (error != 0)
2749		return (error);
2750	if (md->md_version < G_MIRROR_VERSION) {
2751		G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2752		    pp->name, md->md_version, G_MIRROR_VERSION);
2753		g_mirror_update_metadata(disk);
2754	}
2755	return (0);
2756}
2757
2758static void
2759g_mirror_destroy_delayed(void *arg, int flag)
2760{
2761	struct g_mirror_softc *sc;
2762	int error;
2763
2764	if (flag == EV_CANCEL) {
2765		G_MIRROR_DEBUG(1, "Destroying canceled.");
2766		return;
2767	}
2768	sc = arg;
2769	g_topology_unlock();
2770	sx_xlock(&sc->sc_lock);
2771	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2772	    ("DESTROY flag set on %s.", sc->sc_name));
2773	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2774	    ("DESTROYING flag not set on %s.", sc->sc_name));
2775	G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2776	error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2777	if (error != 0) {
2778		G_MIRROR_DEBUG(0, "Cannot destroy %s.", sc->sc_name);
2779		sx_xunlock(&sc->sc_lock);
2780	}
2781	g_topology_lock();
2782}
2783
2784static int
2785g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2786{
2787	struct g_mirror_softc *sc;
2788	int dcr, dcw, dce, error = 0;
2789
2790	g_topology_assert();
2791	G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2792	    acw, ace);
2793
2794	sc = pp->geom->softc;
2795	if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
2796		return (0);
2797	KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2798
2799	dcr = pp->acr + acr;
2800	dcw = pp->acw + acw;
2801	dce = pp->ace + ace;
2802
2803	g_topology_unlock();
2804	sx_xlock(&sc->sc_lock);
2805	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2806	    LIST_EMPTY(&sc->sc_disks)) {
2807		if (acr > 0 || acw > 0 || ace > 0)
2808			error = ENXIO;
2809		goto end;
2810	}
2811	if (dcw == 0 && !sc->sc_idle)
2812		g_mirror_idle(sc, dcw);
2813	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0) {
2814		if (acr > 0 || acw > 0 || ace > 0) {
2815			error = ENXIO;
2816			goto end;
2817		}
2818		if (dcr == 0 && dcw == 0 && dce == 0) {
2819			g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK,
2820			    sc, NULL);
2821		}
2822	}
2823end:
2824	sx_xunlock(&sc->sc_lock);
2825	g_topology_lock();
2826	return (error);
2827}
2828
2829static struct g_geom *
2830g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
2831{
2832	struct g_mirror_softc *sc;
2833	struct g_geom *gp;
2834	int error, timeout;
2835
2836	g_topology_assert();
2837	G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2838	    md->md_mid);
2839
2840	/* One disk is minimum. */
2841	if (md->md_all < 1)
2842		return (NULL);
2843	/*
2844	 * Action geom.
2845	 */
2846	gp = g_new_geomf(mp, "%s", md->md_name);
2847	sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2848	gp->start = g_mirror_start;
2849	gp->orphan = g_mirror_orphan;
2850	gp->access = g_mirror_access;
2851	gp->dumpconf = g_mirror_dumpconf;
2852
2853	sc->sc_id = md->md_mid;
2854	sc->sc_slice = md->md_slice;
2855	sc->sc_balance = md->md_balance;
2856	sc->sc_mediasize = md->md_mediasize;
2857	sc->sc_sectorsize = md->md_sectorsize;
2858	sc->sc_ndisks = md->md_all;
2859	sc->sc_flags = md->md_mflags;
2860	sc->sc_bump_id = 0;
2861	sc->sc_idle = 1;
2862	sc->sc_last_write = time_uptime;
2863	sc->sc_writes = 0;
2864	sx_init(&sc->sc_lock, "gmirror:lock");
2865	bioq_init(&sc->sc_queue);
2866	mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2867	bioq_init(&sc->sc_regular_delayed);
2868	bioq_init(&sc->sc_inflight);
2869	bioq_init(&sc->sc_sync_delayed);
2870	LIST_INIT(&sc->sc_disks);
2871	TAILQ_INIT(&sc->sc_events);
2872	mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2873	callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
2874	sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2875	gp->softc = sc;
2876	sc->sc_geom = gp;
2877	sc->sc_provider = NULL;
2878	/*
2879	 * Synchronization geom.
2880	 */
2881	gp = g_new_geomf(mp, "%s.sync", md->md_name);
2882	gp->softc = sc;
2883	gp->orphan = g_mirror_orphan;
2884	sc->sc_sync.ds_geom = gp;
2885	sc->sc_sync.ds_ndisks = 0;
2886	error = kthread_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
2887	    "g_mirror %s", md->md_name);
2888	if (error != 0) {
2889		G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
2890		    sc->sc_name);
2891		g_destroy_geom(sc->sc_sync.ds_geom);
2892		mtx_destroy(&sc->sc_events_mtx);
2893		mtx_destroy(&sc->sc_queue_mtx);
2894		sx_destroy(&sc->sc_lock);
2895		g_destroy_geom(sc->sc_geom);
2896		free(sc, M_MIRROR);
2897		return (NULL);
2898	}
2899
2900	G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
2901	    sc->sc_name, sc->sc_ndisks, sc->sc_id);
2902
2903	sc->sc_rootmount = root_mount_hold("GMIRROR");
2904	G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2905	/*
2906	 * Run timeout.
2907	 */
2908	timeout = g_mirror_timeout * hz;
2909	callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
2910	return (sc->sc_geom);
2911}
2912
2913int
2914g_mirror_destroy(struct g_mirror_softc *sc, int how)
2915{
2916	struct g_mirror_disk *disk;
2917	struct g_provider *pp;
2918
2919	g_topology_assert_not();
2920	if (sc == NULL)
2921		return (ENXIO);
2922	sx_assert(&sc->sc_lock, SX_XLOCKED);
2923
2924	pp = sc->sc_provider;
2925	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
2926		switch (how) {
2927		case G_MIRROR_DESTROY_SOFT:
2928			G_MIRROR_DEBUG(1,
2929			    "Device %s is still open (r%dw%de%d).", pp->name,
2930			    pp->acr, pp->acw, pp->ace);
2931			return (EBUSY);
2932		case G_MIRROR_DESTROY_DELAYED:
2933			G_MIRROR_DEBUG(1,
2934			    "Device %s will be destroyed on last close.",
2935			    pp->name);
2936			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2937				if (disk->d_state ==
2938				    G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2939					g_mirror_sync_stop(disk, 1);
2940				}
2941			}
2942			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
2943			return (EBUSY);
2944		case G_MIRROR_DESTROY_HARD:
2945			G_MIRROR_DEBUG(1, "Device %s is still open, so it "
2946			    "can't be definitely removed.", pp->name);
2947		}
2948	}
2949
2950	g_topology_lock();
2951	if (sc->sc_geom->softc == NULL) {
2952		g_topology_unlock();
2953		return (0);
2954	}
2955	sc->sc_geom->softc = NULL;
2956	sc->sc_sync.ds_geom->softc = NULL;
2957	g_topology_unlock();
2958
2959	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2960	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
2961	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
2962	sx_xunlock(&sc->sc_lock);
2963	mtx_lock(&sc->sc_queue_mtx);
2964	wakeup(sc);
2965	mtx_unlock(&sc->sc_queue_mtx);
2966	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
2967	while (sc->sc_worker != NULL)
2968		tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
2969	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
2970	sx_xlock(&sc->sc_lock);
2971	g_mirror_destroy_device(sc);
2972	free(sc, M_MIRROR);
2973	return (0);
2974}
2975
2976static void
2977g_mirror_taste_orphan(struct g_consumer *cp)
2978{
2979
2980	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
2981	    cp->provider->name));
2982}
2983
2984static struct g_geom *
2985g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
2986{
2987	struct g_mirror_metadata md;
2988	struct g_mirror_softc *sc;
2989	struct g_consumer *cp;
2990	struct g_geom *gp;
2991	int error;
2992
2993	g_topology_assert();
2994	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
2995	G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
2996
2997	gp = g_new_geomf(mp, "mirror:taste");
2998	/*
2999	 * This orphan function should be never called.
3000	 */
3001	gp->orphan = g_mirror_taste_orphan;
3002	cp = g_new_consumer(gp);
3003	g_attach(cp, pp);
3004	error = g_mirror_read_metadata(cp, &md);
3005	g_detach(cp);
3006	g_destroy_consumer(cp);
3007	g_destroy_geom(gp);
3008	if (error != 0)
3009		return (NULL);
3010	gp = NULL;
3011
3012	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
3013		return (NULL);
3014	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3015		return (NULL);
3016	if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3017		G_MIRROR_DEBUG(0,
3018		    "Device %s: provider %s marked as inactive, skipping.",
3019		    md.md_name, pp->name);
3020		return (NULL);
3021	}
3022	if (g_mirror_debug >= 2)
3023		mirror_metadata_dump(&md);
3024
3025	/*
3026	 * Let's check if device already exists.
3027	 */
3028	sc = NULL;
3029	LIST_FOREACH(gp, &mp->geom, geom) {
3030		sc = gp->softc;
3031		if (sc == NULL)
3032			continue;
3033		if (sc->sc_sync.ds_geom == gp)
3034			continue;
3035		if (strcmp(md.md_name, sc->sc_name) != 0)
3036			continue;
3037		if (md.md_mid != sc->sc_id) {
3038			G_MIRROR_DEBUG(0, "Device %s already configured.",
3039			    sc->sc_name);
3040			return (NULL);
3041		}
3042		break;
3043	}
3044	if (gp == NULL) {
3045		gp = g_mirror_create(mp, &md);
3046		if (gp == NULL) {
3047			G_MIRROR_DEBUG(0, "Cannot create device %s.",
3048			    md.md_name);
3049			return (NULL);
3050		}
3051		sc = gp->softc;
3052	}
3053	G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3054	g_topology_unlock();
3055	sx_xlock(&sc->sc_lock);
3056	error = g_mirror_add_disk(sc, pp, &md);
3057	if (error != 0) {
3058		G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3059		    pp->name, gp->name, error);
3060		if (LIST_EMPTY(&sc->sc_disks)) {
3061			g_cancel_event(sc);
3062			g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3063			g_topology_lock();
3064			return (NULL);
3065		}
3066		gp = NULL;
3067	}
3068	sx_xunlock(&sc->sc_lock);
3069	g_topology_lock();
3070	return (gp);
3071}
3072
3073static int
3074g_mirror_destroy_geom(struct gctl_req *req __unused,
3075    struct g_class *mp __unused, struct g_geom *gp)
3076{
3077	struct g_mirror_softc *sc;
3078	int error;
3079
3080	g_topology_unlock();
3081	sc = gp->softc;
3082	sx_xlock(&sc->sc_lock);
3083	g_cancel_event(sc);
3084	error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3085	if (error != 0)
3086		sx_xunlock(&sc->sc_lock);
3087	g_topology_lock();
3088	return (error);
3089}
3090
3091static void
3092g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3093    struct g_consumer *cp, struct g_provider *pp)
3094{
3095	struct g_mirror_softc *sc;
3096
3097	g_topology_assert();
3098
3099	sc = gp->softc;
3100	if (sc == NULL)
3101		return;
3102	/* Skip synchronization geom. */
3103	if (gp == sc->sc_sync.ds_geom)
3104		return;
3105	if (pp != NULL) {
3106		/* Nothing here. */
3107	} else if (cp != NULL) {
3108		struct g_mirror_disk *disk;
3109
3110		disk = cp->private;
3111		if (disk == NULL)
3112			return;
3113		g_topology_unlock();
3114		sx_xlock(&sc->sc_lock);
3115		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3116		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3117			sbuf_printf(sb, "%s<Synchronized>", indent);
3118			if (disk->d_sync.ds_offset == 0)
3119				sbuf_printf(sb, "0%%");
3120			else {
3121				sbuf_printf(sb, "%u%%",
3122				    (u_int)((disk->d_sync.ds_offset * 100) /
3123				    sc->sc_provider->mediasize));
3124			}
3125			sbuf_printf(sb, "</Synchronized>\n");
3126		}
3127		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3128		    disk->d_sync.ds_syncid);
3129		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3130		    disk->d_genid);
3131		sbuf_printf(sb, "%s<Flags>", indent);
3132		if (disk->d_flags == 0)
3133			sbuf_printf(sb, "NONE");
3134		else {
3135			int first = 1;
3136
3137#define	ADD_FLAG(flag, name)	do {					\
3138	if ((disk->d_flags & (flag)) != 0) {				\
3139		if (!first)						\
3140			sbuf_printf(sb, ", ");				\
3141		else							\
3142			first = 0;					\
3143		sbuf_printf(sb, name);					\
3144	}								\
3145} while (0)
3146			ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3147			ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3148			ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3149			ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3150			    "SYNCHRONIZING");
3151			ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3152			ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3153#undef	ADD_FLAG
3154		}
3155		sbuf_printf(sb, "</Flags>\n");
3156		sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3157		    disk->d_priority);
3158		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3159		    g_mirror_disk_state2str(disk->d_state));
3160		sx_xunlock(&sc->sc_lock);
3161		g_topology_lock();
3162	} else {
3163		g_topology_unlock();
3164		sx_xlock(&sc->sc_lock);
3165		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3166		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3167		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3168		sbuf_printf(sb, "%s<Flags>", indent);
3169		if (sc->sc_flags == 0)
3170			sbuf_printf(sb, "NONE");
3171		else {
3172			int first = 1;
3173
3174#define	ADD_FLAG(flag, name)	do {					\
3175	if ((sc->sc_flags & (flag)) != 0) {				\
3176		if (!first)						\
3177			sbuf_printf(sb, ", ");				\
3178		else							\
3179			first = 0;					\
3180		sbuf_printf(sb, name);					\
3181	}								\
3182} while (0)
3183			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3184#undef	ADD_FLAG
3185		}
3186		sbuf_printf(sb, "</Flags>\n");
3187		sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3188		    (u_int)sc->sc_slice);
3189		sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3190		    balance_name(sc->sc_balance));
3191		sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3192		    sc->sc_ndisks);
3193		sbuf_printf(sb, "%s<State>", indent);
3194		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3195			sbuf_printf(sb, "%s", "STARTING");
3196		else if (sc->sc_ndisks ==
3197		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3198			sbuf_printf(sb, "%s", "COMPLETE");
3199		else
3200			sbuf_printf(sb, "%s", "DEGRADED");
3201		sbuf_printf(sb, "</State>\n");
3202		sx_xunlock(&sc->sc_lock);
3203		g_topology_lock();
3204	}
3205}
3206
3207static void
3208g_mirror_shutdown_pre_sync(void *arg, int howto)
3209{
3210	struct g_class *mp;
3211	struct g_geom *gp, *gp2;
3212	struct g_mirror_softc *sc;
3213	int error;
3214
3215	mp = arg;
3216	DROP_GIANT();
3217	g_topology_lock();
3218	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3219		if ((sc = gp->softc) == NULL)
3220			continue;
3221		/* Skip synchronization geom. */
3222		if (gp == sc->sc_sync.ds_geom)
3223			continue;
3224		g_topology_unlock();
3225		sx_xlock(&sc->sc_lock);
3226		g_cancel_event(sc);
3227		error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3228		if (error != 0)
3229			sx_xunlock(&sc->sc_lock);
3230		g_topology_lock();
3231	}
3232	g_topology_unlock();
3233	PICKUP_GIANT();
3234}
3235
3236static void
3237g_mirror_init(struct g_class *mp)
3238{
3239
3240	g_mirror_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
3241	    g_mirror_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
3242	if (g_mirror_pre_sync == NULL)
3243		G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3244}
3245
3246static void
3247g_mirror_fini(struct g_class *mp)
3248{
3249
3250	if (g_mirror_pre_sync != NULL)
3251		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mirror_pre_sync);
3252}
3253
3254DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3255